Glaucoma is the second leading cause of blindness in the developed world and causes progressive loss of the peripheral visual field. While visual loss caused by glaucoma is currently irreversible, clinical intervention is most effective if the disease is caught at an early stage, when catastrophic field loss can be averted. Unfortunately existing screening techniques can only detect glaucoma once significant visual impairment has occurred. Although visual deficits in glaucoma are thought to be attributable to programmed cell death (apoptosis) of retinal ganglion cells (RGCs) it is now clear that cell-death is the endpoint of a gradual deterioration in RGC-function. Effective diagnostics cannot wait for cell death, but must measure a behavioral impact of RGC dysfunction. When screening fails, the clinician is particularly reliant on the patients self-diagnosing. Unfortunately more than 50% of people who have diagnosable glaucoma are unaware of it. This, along with poor screening sensitivity has long-term implications for the effective management of an increasingly prevalent disease. This proposal assesses a more efficient and more sensitive motion screening technique that may help detect RGC dysfunction earlier, facilitating prompt clinical intervention to slow the progression of glaucoma. We examine binocular vision, filling-in and compensatory eye movements that may obscure detection of progressive visual impairment and prevent patients from self-diagnosing at an earlier stage of the disease. The overall aim of this proposal is to identify signs of glaucoma that may help bring patients to clinic before catastrophic glaucomatous visual field loss has occurred. Such early intervention allows clinical management of glaucoma to be most effective and so relieves the burden of visual impairment. PUBLIC HEALTH RELEVANCE: Glaucoma is the second leading cause of blindness in the developed world and its incidence is set to rise as the population ages. While visual loss caused by glaucoma is currently irreversible, clinical intervention is most effective if the disease is detected and treated at an early stage, when catastrophic field loss can be averted. The proposed program of research develops new diagnostics that are sensitive to the early stages of neuro-degeneration in glaucoma.